MONDAY, Nov. 23, 2015 (HealthDay News) -- Young women who survive a heart attack or stroke may not be out of danger once they recover, European researchers say.

These women could continue to face drastically increased risk of death -- or another heart attack or stroke -- for a long time after their initial life-threatening illness, according to a new study published Nov. 23 in JAMA Internal Medicine.

"Our results show that the increase in risk is persistent over a long time, making it even more clear that women should keep their regular checkups and try to maintain a healthy lifestyle, even if their first event was years ago," said co-author Bob Siegerink, group leader of epidemiology at the Charite Center for Stroke Research in Berlin, Germany.

Overall death rates are 3.7 times higher in women who've had a heart attack and 1.8 times higher in women who've had a stroke, compared with healthy women, researchers found.

Women who've had a heart attack will have a 20-times increased risk of a second heart attack, and a tripled risk of a first stroke, according to findings.

At the same time, female stroke victims will have an 18-fold increased risk of another stroke and an almost six times greater risk of a first heart attack.

Researchers based these findings on 226 women who had a heart attack, 160 women who had a stroke and 782 healthy women. All live in the Netherlands. The heart attack and stroke patients were about 40 years old on average at the time of their health event. They were followed for a median of almost 19 years -- half more than that, half less.

Siegerink noted that the women were most likely to suffer a second occurrence of whatever struck them the first time, be it a heart attack or a stroke.

"Basically, the long-term risk of cardiovascular events are 'true to type', which is an indication that the mechanisms that lead to cardiovascular recurrence are disease-specific," he said.

These results show that young women need to take their heart health more seriously, particularly if they've had a heart attack or stroke, said Dr. Suzanne Steinbaum, director of Women's Heart Health at Lenox Hill Hospital in New York City.

Heart disease is the leading cause of death for women in the United States, killing nearly 422,000 each year, according to the U.S. Centers for Disease Control and Prevention.

"If a young woman has a cardiovascular event, there needs to be aggressive secondary prevention to make sure this never happens again, because the risk of dying is so much higher for her," Steinbaum said.

"When heart attacks happen to younger women and they feel better, it's good they get back to their normal lives but they have to be mindful of prevention throughout their life," said Goldberg, who also is a spokeswoman for the American Heart Association.

In a way, these results aren't news. Researchers have long known that anyone who has a heart attack or stroke is at increased risk of another one, compared with people who've never had one, Goldberg said.

But young women pursuing a career and raising a family often put themselves last in line for medical care, said Dr. Carl Pepine, a professor of cardiovascular medicine at the University of Florida College of Medicine.

These women may not realize that they are at risk for a heart attack or stroke, or they might shrug off that risk as they get the kids off to school or prepare for a busy work day, said Pepine, a past president of the American College of Cardiology and a member of its Cardiovascular Disease in Women Committee.

"Young women are not free of cardiovascular disease, and when they have an event they are at heightened risk of bad things happening over the long term," he said. "Women need to understand that they have to put themselves ahead of other obligations, and protect their heart health."